• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 7
  • 3
  • 3
  • 2
  • 1
  • 1
  • Tagged with
  • 20
  • 4
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Pressure, leakage and energy management in water distribution systems

AbdelMeguid, Hossam Saadeldin January 2011 (has links)
A fast and efficient method to calculate time schedules for internal and boundary PRVs and flow modulation curves has been developed and implemented. Both time and flow modulation can be applied to a single inlet DMA. The time modulation methodology is based on solving a nonlinear programming problem (NLP). In addition, Genetic Algorithms (GA) has been proposed and investigated to calculate the optimal coefficients of a second order relationship between the flow and the outlet pressure for a PRV to minimize the background leakage. The obtained curve can be subsequently implemented using a flow modulation controller in a feedback control scheme. The Aquai-Mod® is a hydraulic device to control and modulate the outlet pressure of a PRV according to the valve flow. The controller was experimentally tested to assess its performance and functionality in different conditions and operating ranges. The mathematical model of the controller has been developed and solved, in both steady state and dynamic conditions. The results of the model have been compared with the experimental data and showed a good agreement in the magnitude and trends. A new method for combined energy and pressure management via integration and coordination of pump scheduling with pressure control aspects has been created. The method is based on formulating and solving an optimisation NLP problem and involves pressure dependent leakage. The cost function of the optimisation problem represents the total cost of water treatment and pumping energy. Developed network scheduling algorithm consists of two stages. The first stage involves solving a continuous problem, where operation of each pump is described by continuous variable. Subsequently, the second stage continuous pump schedules are discretised using heuristic algorithm. Another area of research has been developing optimal feedback rules using GA to control the operation of pump stations. Each pump station has a rule described by two water levels in a downstream reservoir and a value of pump speed for each tariff period. The lower and upper water switching levels of the downstream reservoir correspond to the pump being “ON” or “OFF”. The achieved similar energy cost per 1 Ml of pumped water. In the considered case study, the optimal feedback rules had advantage of small number of ON/OFF switches, which increase the pump stations lifetime and reduce the maintenance cost as well.
2

APLICAÇÃO DE HEURÍSTICAS E META-HEURÍSTICAS NO DESENVOLVIMENTO DE UM SISTEMA DE APOIO A DECISÃO PARA RESOLUÇÃO DE PROBLEMAS DE ROTEAMENTO DE VEÍCULOS APLICADOS À AGRICULTURA

Duda, Robson Fernando 28 February 2014 (has links)
Made available in DSpace on 2017-07-21T14:19:39Z (GMT). No. of bitstreams: 1 Robson Fernando Duda.pdf: 3342961 bytes, checksum: 3f61d3a8f1dcfb461c6860c82d3f54db (MD5) Previous issue date: 2014-02-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This paper presents a solution to the routing problem of vehicles with homogeneous fleet. To do so, heuristic and metaheuristic based algorithms applied towards the development of a decision support system, with georeferenced interface were developed. The algorithms had as base heuristic methods built in two phases, besides a metaheuristic. The interface layer used as visualization component is based in cartographic data that indicates the location of the points to be assisted and the paths that connects them, forming a road system represented using the Google Maps® API. The algorithms were validated using instances from the literature, presenting satisfactory results regarding optimization based in the methods that were used, showing that it is possible the usage of the developed system in the distribution of agricultural products. / Este trabalho apresenta uma solução para o problema de roteamento de veículos com frotas homogêneas. Para tanto, foram desenvolvidos algoritmos baseados em heurísticas e meta-heurísticas aplicadas ao desenvolvimento de um sistema de apoio a decisão, com interface georreferenciada. Os algoritmos tiveram como base métodos heurísticos construtivos e em duas fases, além de uma meta-heurística. A camada de interface utilizada como componente de visualização é baseada em dados cartográficos que indicam a localização dos pontos a serem atendidos e as vias que os interligam, formando a malha viária que é representada utilizando a API do Google Maps®. Os algoritmos foram validados utilizando instâncias da literatura, apresentando resultados satisfatórios em relação a otimização baseada nos métodos utilizados, mostrando ser possível a utilização do sistema desenvolvido para a distribuição de produtos agrícolas.
3

Cortical Auditory Functional Activation By Cortico-Striato-Thalamo-Cortical Circuits

January 2014 (has links)
abstract: ABSTRACT Auditory hallucinations are a characteristic symptom of schizophrenia. Research has documented that the auditory cortex is metabolically activated when this process occurs, and that imbalances in the dopaminergic transmission in the striatum contribute to its physiopathology. Most animal models have focused the effort on pharmacological approaches like non-competitive N-methyl-D-aspartate (NMDA) receptor antagonists to produce activation of the auditory cortex, or dopamine antagonists to alleviate it. I hypothesize that these perceptual phenomena can be explained by an imbalance activation of spiny projecting neurons in the striatal pathways, whereby supersensitive postsynaptic D2-like receptor, signaling in the posterior caudatoputamen generates activation of the auditory cortex. Therefore, I characterized the neuroanatomical component involved in the activation of the auditory cortex. I evaluated the participation of dopamine D2-like receptor using selective dopamine antagonist manipulations and identified the circuits related to the auditory cortex by retrograde trans-synaptic tracing using pseudorabies virus (PRV-152). My results show that dopamine infused in the posterior caudatoputamen dose dependently increases the transcription of the immediate early gene, zif268 in the auditory cortex, predominantly in layers III and IV, but also in cortical columns, suggesting enhanced functional auditory activity. This indicates the participation of the posterior striatum in the modulation of the secondary auditory cortex. I was able to demonstrate also that a coinfusion of a selective dopamine D2-like receptor antagonist, eticlopride and dopamine, attenuate the activation of the auditory cortex. Furthermore, using PRV-152 I delineate the distinctive circuit by axial mapping of the infected neurons. Thus, I found secondary projections from the posterior caudatoputamen that synapse in the thalamus before reaching the auditory cortex. These striatal projections correspond to the same brain region affected by dopamine during auditory cortical activation. My results further characterized a mechanism to generate intrinsic perception of sound that may be responsible for auditory hallucinations. I propose this paradigm may elucidate insight on the biological basis of psychotic behavior. / Dissertation/Thesis / Figure 9C. 3D brain reconstruction after 48 hours of PRV-152 inoculations / Figure 9A. 3D brain reconstruction after 24 h postinoculation / Figure 9B. 3D brain reconstruction after 36 h postinoculation / Doctoral Dissertation Neuroscience 2014
4

Analýza dopadu vývoje změn dotační politiky na finanční situaci zemědělských podniků / Modification of subsidy policy and its impact on financial health of agricultural companies

KUNDRÁTOVÁ, Jana January 2009 (has links)
This thesis focused on examination of influence of changes structure and volume of grants on financial situation of selected farming companies. In the first part, the history of SZP, legal form of EU and CR and first of all the survey of grants which were possible to obtain in years 2004 {--} 2006 and after a year 2007 is stated. The second part of the thesis is attends to evaluation of financial situation of selected farming companies, which are dividend into 2 groups according to area where they are farming (region of LFA, marginal area). Resalts of analyse are stated in this part. Changes which occured in endowment policy in new plan period 2007 {--} 2013 are stated in this part too.
5

Analýza podmínek využití prostředků z fondu EAFRD v ZD Hluboké Mašůvky / Analysis of conditions of a usage resources from the fund EAFRD in FC Hluboké Mašůvky

KAMARÁDOVÁ, Radka January 2008 (has links)
This thesis concentrates on pumping and a usage of the EAFRD resources, on conditions that are the applicants asked to fulfil in order to use these dotation resources. A practical example is a compilation of a project for the agricultural cooperation Hluboké Mašůvky.
6

Úloha programu LEADER v rozvoji mikroregionu Chelčicko-Lhenicko / The role of the LEADER programme in the development of the Chelčicko-Lhenicko region

PEROUTKA, Jiří January 2008 (has links)
The purpose of this thesis is to describe the LEADER programme and to determine its potential applications in the Chelčicko-Lhenicko region. The theoretical portion of the thesis defines both the details of the structural funds for the implementation periods 2004 {--} 2006 and 2007 {--} 2013, as well as the contents page of the LEADER+ programme, which includes a brief overview of the LAG {--} Local action group. The practical portion focuses on describing the monitored area and on the potential applications of the LEADER+ programme in the Chelčicko-Lhenicko region, as evaluated using a SWOT analyses. The conclusion of the thesis presents the benefits of the LEADER programme for the monitored region and includes other suggested LEADER+ type programmes.
7

Etude des relations entre la structure des molécules odorantes et leurs équilibres rétention-libération entre phase vapeur et gels laitiers / Study of relationships between the structure of aroma compounds and their retention-release between vapour phase and dairy gels

Merabtine, Yacine 06 October 2010 (has links)
Une approche intégrée physicochimie et relations structure-activité a été mise en œuvre afin d’étudier le phénomène rétention-libération des composés d’arôme dans un gel laitier allégé additionné de pectine. Notre objectif était d’identifier les propriétés moléculaires qui régissent ce phénomène en supposant que la modification de la structure entraîne forcement un changement dans la rétention-libération des composés d’arôme. Dans ce but, nous avons déterminé les coefficients de partage de 28 composés d’arôme dans l’eau, dans des gels de pectine et dans des gels laitiers avec ou sans de pectine, à l’équilibre en utilisant la méthode PRV (Phase Ratio Variation). Nous avons ensuite effectué une étude des relations structure-rétention en évaluant les corrélations entre les coefficients de partage et quatre descripteurs traduisant quatre propriétés moléculaires : l’hydrophobie globale, la surface moléculaire, la polarisabilité et la densité de charge négative. Notre démarche d’étude des relations structure-activité (Structure-Activity Relationships, SAR) consistait à étudier des composés d’arôme appartenant à une gamme de structures variée, dans un même ensemble, puis en sous-groupes en fonction d’une particularité structurale donnée afin de révéler les particularités de la structure qui influent sur le phénomène rétention-libération. La comparaison des rétentions entre les milieux n’a pas montré l’existence d’un effet pectine. Les études des relations structure-activité ont montré l’impact de certaines particularités structurales telles que la ramification et la double liaison sur la rétention. Elles ont également montré que l’hydrophobie globale des molécules n’était pas la propriété moléculaire la plus à même d’expliquer les phénomènes impliqués dans les interactions de molécules odorantes avec les constituants du milieu (eau ou gel laitier). La surface et la polarisabilité rendent mieux compte des rétentions des composés d’arôme. Les corrélations impliquant la surface, la polarisabilité et l’hydrophobie globale, confirment que les interactions de type van der Waals (essentiellement Keesom et London) sont favorables à la rétention dans les gels laitiers et défavorables à la rétention dans l’eau. De même, les corrélations impliquant la densité de charge montrent que les interactions polaires sont favorables à la rétention dans l’eau. Notre choix de départ, qui consistait à faire varier la structure des composés d’arôme afin d’apprécier son effet sur le phénomène rétention-libération des composés d’arôme, s’est avéré concluant, et le groupe de 28 composés permet effectivement de mener une étude quantitative des relations structure-propriété. Cette démarche QSAR pourra se transposer à des systèmes alimentaires simples ou complexes. / An integrated approach physicochemistry and structures activity relationships has been carried out to study the aroma compounds retention-release phenomenon in a fat free dairy gel added with pectin. This study aimed to identify the molecular properties that govern this phenomenon assuming that modifying the structure leads automatically to a change in the retention-release of aroma compounds. For this purpose, we have determined the partition coefficients of 28 aroma compounds in water, in pectin gels and in dairy gels supplemented or not supplemented with pectin, at equilibrium conditions using the PRV method (Phase Ratio Variation). Then, we have performed a structure-retention relationships study for the aroma compounds by estimating correlations between the partition coefficients and four descriptors representing four molecular properties: Global hydrophobicity, molecular area, polarizability and negative charge density. Our methodology concerning the structure-activity relationships study (SAR) consisted on studying a varied range of aroma compounds in terms of molecular structure, first taking into account all of them in the same set, then in separated subgroups according to a given structural particularity in order to reveal which structural particularities control the retention-release phenomenon. The comparison of retention between the several media has not shown any effect of pectin. Structure-activity relationships studies have shown the impact of some structural particularities like branching and double linking. They have also shown that the global hydrophobicity was not the best molecular property to explain the phenomena involved in the interactions between aroma compounds and matrix components (water and dairy gel). Molecular area and polarizability are more likely to report of aroma retention-release. Correlations implying molecular area, polarizability or global hydrophobicity confirm that van der Waals (especially Keesom and London) are involved in the retention in dairy gels and unfavourable in the retention in water. Correlations implying negative charge density show that polar interactions are favourable in the retention in water as well. Our strategy which consisted on varying the structure of aroma compounds to exanimate its effect on the retention-release phenomenon was found to be effective, and the set of 28 aroma compounds allowed as leading a quantitative structure-property relationships study. This QSAR approach can be transposed to simple or complex food systems.
8

Kvalitetssäkring av Patent- och registreringsverket : EPO-praxis som förebild för svensk handläggning av patent / Assurance of Quality at the Swedish Patent Office : EPO-practice as a Paragon for the Swedish Formal Handling of the Patent Examination Process

Sigfridsson, Isac, von Düben, Martin January 2015 (has links)
Svensk patenträtt har i stor omfattning harmoniserats med praxis utvecklad av det europeiska patentverket (EPO), vad avser patenterbarhetskriterier. Anledningen till harmoniseringen har motiverats av att det ska bli en mer enhetlig bedömning av patent i Europa. Harmoniseringen har i vart fall inte innefattat så kallad formell praxis, som innefattar regler om hand­läggandet hos det svenska patentverket, i förhållande till handläggandet av det vid EPO.   Vid Sveriges anslutning till European Patent Convention (EPC) år 1978, förespråkades att det svenska patentverket ansågs hålla en godtagbar standard i sin handläggning, men att det fram­tida förhållandet mellan svensk patenträtt och EPC kunde komma att innebära förändring om kvalitetsnivån inte kunde anses tillräcklig hög. Efter ett nyligen taget beslut av Patentbesvärsrätten (PBR) har Patent- och registreringsverkets (PRV) handläggning ifrågasatts, varför författarna valt att undersöka om en förändring av hand­läggningen vid PRV bör genomföras, i enlighet med det förslag som framställs i proposition 1977/78:1, med beaktande av praxis utvecklad av EPO.   I uppsatsen redogörs för hur EPO har tydligare regler avseende patent­ärenden än vad PRV har, varför en harmonisering av detta område bör diskuteras för säkerställandet av hög kvalitet vid handläggningen hos det svenska patentverket. Det är författarnas uppfattning att en ofullständig harmonisering även av formella regler resulterar i ett problem för säkerställandet av rättssäkerheten, eftersom lagregleringen i Sverige kan anses bristfällig. Således är det av intresse för svensk patenträtt att ta hänsyn till formell praxis utvecklad av EPO, alternativt, genom lagstiftningsförfarande, reglera bristen av tydliga regler.
9

Etude des relations entre la structure des molécules odorantes et leurs équilibres rétention-libération entre phase vapeur et gels laitiers

Merabtine, Yacine 06 October 2010 (has links) (PDF)
Une approche intégrée physicochimie et relations structure-activité a été mise en œuvre afin d'étudier le phénomène rétention-libération des composés d'arôme dans un gel laitier allégé additionné de pectine. Notre objectif était d'identifier les propriétés moléculaires qui régissent ce phénomène en supposant que la modification de la structure entraîne forcement un changement dans la rétention-libération des composés d'arôme. Dans ce but, nous avons déterminé les coefficients de partage de 28 composés d'arôme dans l'eau, dans des gels de pectine et dans des gels laitiers avec ou sans de pectine, à l'équilibre en utilisant la méthode PRV (Phase Ratio Variation). Nous avons ensuite effectué une étude des relations structure-rétention en évaluant les corrélations entre les coefficients de partage et quatre descripteurs traduisant quatre propriétés moléculaires : l'hydrophobie globale, la surface moléculaire, la polarisabilité et la densité de charge négative. Notre démarche d'étude des relations structure-activité (Structure-Activity Relationships, SAR) consistait à étudier des composés d'arôme appartenant à une gamme de structures variée, dans un même ensemble, puis en sous-groupes en fonction d'une particularité structurale donnée afin de révéler les particularités de la structure qui influent sur le phénomène rétention-libération. La comparaison des rétentions entre les milieux n'a pas montré l'existence d'un effet pectine. Les études des relations structure-activité ont montré l'impact de certaines particularités structurales telles que la ramification et la double liaison sur la rétention. Elles ont également montré que l'hydrophobie globale des molécules n'était pas la propriété moléculaire la plus à même d'expliquer les phénomènes impliqués dans les interactions de molécules odorantes avec les constituants du milieu (eau ou gel laitier). La surface et la polarisabilité rendent mieux compte des rétentions des composés d'arôme. Les corrélations impliquant la surface, la polarisabilité et l'hydrophobie globale, confirment que les interactions de type van der Waals (essentiellement Keesom et London) sont favorables à la rétention dans les gels laitiers et défavorables à la rétention dans l'eau. De même, les corrélations impliquant la densité de charge montrent que les interactions polaires sont favorables à la rétention dans l'eau. Notre choix de départ, qui consistait à faire varier la structure des composés d'arôme afin d'apprécier son effet sur le phénomène rétention-libération des composés d'arôme, s'est avéré concluant, et le groupe de 28 composés permet effectivement de mener une étude quantitative des relations structure-propriété. Cette démarche QSAR pourra se transposer à des systèmes alimentaires simples ou complexes.
10

Regional Affiliation: An Examination of Rio Viejo Middens as Evidence for Scaled-up Practice at Surrounding Sites.

Lucido, Carlo 01 January 2015 (has links)
This research project analyzes 5 middens from the Lower Rio Verde valley sites of Río Viejo and Yugüe, Oaxaca, Mexico, during the Terminal Formative period (150 BC to AD 250). The middens are analyzed to further our understanding of socio-political events in public spaces at both sites during this time. The study suggests a greater distinction in use of public spaces between the two sites than within Río Viejo. Frameworks established by Dietler and Hayden for the analysis of feasts do not seem to apply well to the middens analyzed here. Although I argue that evidence from Rio Viejo's middens does not dispute the viability of previous arguments regarding Terminal Formative Río Viejo ritual authorities', potentially elites, efforts to create regional-scale political affiliations, the level to which middens at Río Viejo are evidence of “scaled-up” versions of local practices at outlying sites is inconclusive. Though there is potential for larger feasts at Río Viejo, taken alone the Yugüe midden appears larger. The Río Viejo middens demonstrate greater likelihood for the diminished conspicuousness of status differentiation during the associated events.

Page generated in 0.0288 seconds